// class Person {
//   public readonly _name: string;
//   constructor(name: string) {
//     this._name = name;
//   }
// }
// const person = new Person("TT");
// // person._name = "PP";
// console.log(person._name);

abstract class User {
  abstract skill(): void;
}

class Waiter extends User {
  skill() {
    console.log("trans water");
  }
}
class Base extends User {
  skill() {
    console.log("hand");
  }
}
class Senior extends User {
  skill() {
    console.log("all");
  }
}
